It is often desired to know the angle of inclination of a vehicle or vehicle member with respect to the road or ground. For example, the in-vehicle inclination angle can be an important parameter for vehicle navigation and positioning, especially in high-density cities with multi-level road structures. In another example, it can be useful to monitor the positioning of construction equipment vehicle members, such as a boom, dipper stick, bucket, grader, scraper, and chassis platform. Generally, the in-vehicle inclination angle is measured with an inclinometer that is fixed to the vehicle. These fixed-inclinometers require an installation calibration where it is assumed that there will be no relative misalignment pitch offset angle between the inclinometer and the body frame of the vehicle, i.e., the angle measured is the road grade without an offset of the pitch angle between the positioning of the inclinometer and the actual road grade. Therefore, fixed-inclinometers can have drawbacks. For example, fixed-inclinometers often cannot distinguish between gravitational acceleration and non-gravitational sources of acceleration. Linear, or translational, motions and vibrations can also produce measurable accelerations. These sources of acceleration can result in undesired and erroneous output signals from an inclinometer. In some cases, the undesired signals can be large in comparison to the desired inclination measurement, rendering the sensor output unreliable and unusable.